Use of Conditioned Extracellular Matrix as a Tissue-engineered Tumor Matrisome for Prostate Cancer and Melanoma Immunotherapy.

Background/aim: Decellularized extracellular matrix (ECM) acts as a depot for biochemical factors when conditioned by the growth of cells that are subsequently removed, and in the case of tumors, this ECM depot is known as the matrisome. This study was undertaken to determine whether a tissue-engineered matrisome could be used as an antigenic depot to stimulate protective immunity against tumor regrowth and metastasis following surgical reduction of the tumor.

Materials And Methods: Using two transplanted tumor cell models, the PAIII rat model of prostate cancer and the B16F1 mouse model of melanoma, mice were administered either media (control), a suspension of inactivated tumor cells, extracellular matrix (SIS), or a matrisome engineered through growth and removal of tumor cells on SIS that was then implanted either directly onto the resected tumor bed or at an anatomical site distant to the tumor bed.

Lack of immunogenicity of xenogeneic DNA from porcine biomaterials.

Background: Clinically useful biomaterials are derived from xenogeneic extracellular matrices, but extensive processes often used to remove all residual DNA are detrimental to their proper biological function. We hypothesized that deliberate and repeated injection of DNA extracted from clinically implantable, xenogeneic extracellular matrices might elicit an immune response in a well-established murine model that could ultimately lead to altered extracellular matrix remodeling.

Methods: DNA was purified from unprocessed porcine extracellular matrices and processed extracellular matrices before sterilization (aseptic) and after sterilization.

Characterization of the local wound environment following treatment of chronic leg ulcers with SIS wound matrix.

Background: The SIS Wound Matrix (SISWM) has been shown to improve healing of chronic ulcers over standard of care. In this study, we tested the hypothesis that chronic venous ulcers responsive to treatment with SISWM would more closely mimic an acute wound state as opposed to unresponsive ulcers.

Methods: Serum and wound exudate were collected at baseline and then weekly for up to 12 weeks from 12 patients receiving multiple applications of the SISWM.

Amino acid-based Poly(ester urea) copolymer films for hernia-repair applications.

The use of degradable materials is required to address current performance and functionality shortcomings from biologically-derived tissues and non-resorbable synthetic materials used for hernia mesh repair applications. Herein a series of degradable l-valine-co-l-phenylalanine poly(ester urea) (PEU) copolymers were investigated for soft-tissue repair. Poly[(1-VAL-8)-co-(1-PHE-6)] showed the highest uniaxial mechanical properties (332.

Contemporary concepts in hernia prevention: Selected proceedings from the 2017 International Symposium on Prevention of Incisional Hernias.

Incisional hernia is a frequent complication of midline laparotomy and enterostomal creation and is associated with high morbidity, decreased quality of life, and high costs. The International Symposium on Incisional Hernia Prevention was held October 19-20, 2017, at the InterContinental Hotel in San Francisco, CA, hosted by the Department of Surgery, University of California, San Francisco. One hundred and three attendees included general and plastic surgeons from 9 countries, including principal participants for several of the seminal studies in the field.

Preclinical in Vitro and in Vivo Assessment of Linear and Branched l-Valine-Based Poly(ester urea)s for Soft Tissue Applications.

New polymers are needed to address the shortcomings of commercially available materials for soft tissue repair. Herein, we investigated a series of l-valine-based poly(ester urea)s (PEUs) that vary in monomer composition and the extent of branching as candidate materials for soft tissue repair. The preimplantation Young's moduli (105 ± 30 to 269 ± 12 MPa) for all the PEUs are comparable to those of polypropylene (165 ± 5 MPa) materials currently employed in hernia-mesh repair.

The Role of miR-126 in Critical Limb Ischemia Treatment Using Adipose-Derived Stem Cell Therapeutic Factor Concentrate and Extracellular Matrix Microparticles.

BACKGROUND Paracrine factors secreted by adipose-derived stem cells can be captured, fractionated, and concentrated to produce therapeutic factor concentrate (TFC). The present study examined whether TFC effects could be enhanced by combining TFC with a biological matrix to provide sustained release of factors in the target region. MATERIAL AND METHODS Unilateral hind limb ischemia was induced in rabbits.

Exertional heat illness and acute injury related to ambient wet bulb globe temperature.

Background: The Deepwater Horizon disaster cleanup effort provided an opportunity to examine the effects of ambient thermal conditions on exertional heat illness (EHI) and acute injury (AI).

Methods: The outcomes were daily person-based frequencies of EHI and AI. Exposures were maximum estimated WBGT (WBGTmax) and severity.

Transforming surgery through biomaterial template technology.

Templates inserted into surgical wounds strongly influence the healing responses in humans. The science of these templates, in the form of extracellular matrix biomaterials, is rapidly evolving and improving as the natural interactions with the body become better understood.

Suppression and activation of the malignant phenotype by extracellular matrix in xenograft models of bladder cancer: a model for tumor cell "dormancy".

A major problem in cancer research is the lack of a tractable model for delayed metastasis. Herein we show that cancer cells suppressed by SISgel, a gel-forming normal ECM material derived from Small Intestine Submucosa (SIS), in flank xenografts show properties of suppression and re-activation that are very similar to normal delayed metastasis and suggest these suppressed cells can serve as a novel model for developing therapeutics to target micrometastases or suppressed cancer cells. Co-injection with SISgel suppressed the malignant phenotype of highly invasive J82 bladder cancer cells and highly metastatic JB-V bladder cancer cells in nude mouse flank xenografts.

Augmenting myometrial healing after cesarean delivery: use of an adjuvant biologic graft placement in an ovine model.

We sought to reduce long-term complications after cesarean delivery by improving myometrial healing. Eight sheep (three with twins) underwent cesarean delivery. Hysterotomy sites were repaired in equal parts by suture alone or suture with a juxtaposed graft (Cook Medical, Bloomington, IN).

Addition of nimesulide to small intestinal submucosa biomaterial inhibits postsurgical adhesiogenesis in rats.

Adhesion formation is a common complication in abdominal surgery with incidence as high as 93% and small bowel obstruction a common complication. Because the extracellular matrix material, small intestinal submucosa (SIS), is commonly used in various surgical procedures, methods to inhibit adhesiogenesis are of great interest. This study was undertaken to determine if incorporation of nimesulide (NM), a selective cyclooxygenase (COX)-2 inhibitor, could reduce the extent and tenacity of intraabdominal adhesion formation associated with SIS implantation.

Are biologic grafts effective for hernia repair?: a systematic review of the literature.

Biologic grafts for hernia repair are a relatively new development in the world of surgery. A thorough search of the Medline database for uses of various biologic grafts in hernia shows that the evidence behind their application is plentiful in some areas (ventral, inguinal) and nearly absent in others (parastomal). The assumption that these materials are only suited for contaminated or potentially contaminated surgical fields is not borne out in the literature, with more than 4 times the experience being reported in clean fields and the average success rates being higher (93% vs 87%).

Use of an extracellular matrix material as a vaccine carrier and adjuvant.

Background: The addition of adjuvants frequently enhances the efficacy of vaccine preparations. Interest in the use of vaccines as a means to treat cancer has led to the search for improved adjuvants. Because cancer vaccines based on whole cell preparations might benefit from an adjuvant which enhances expression of antigens expressed during tumor cell growth, we evaluated the utility of an extracellular matrix material, porcine small intestinal submucosa (SIS), as a cancer vaccine adjuvant.

Bioactivity of small intestinal submucosa and oxidized regenerated cellulose/collagen.

Objective: This study examined the bioactivity of porcine small intestinal submucosa (SIS Wound Matrix [SISWM], USP) and oxidized regenerated cellulose/collagen (ORC).

Design: Bioactivity was assessed in vitro as the ability to stimulate neurite outgrowth in rat pheochromocytoma (PC12) cells, proliferation of human fibroblasts, secretion of vascular endothelial growth factor (VEGF) from human fibroblasts, and in an in vivo angiogenesis model. In the angiogenesis model, SISWM and ORC were implanted subcutaneously into the mice, and vessel ingrowth was assessed at day 21 after implantation using fluorescence microangiography and histology.

Rapid biofabrication of tubular tissue constructs by centrifugal casting in a decellularized natural scaffold with laser-machined micropores.

Centrifugal casting allows rapid biofabrication of tubular tissue constructs by suspending living cells in an in situ cross-linkable hydrogel. We hypothesize that introduction of laser-machined micropores into a decellularized natural scaffold will facilitate cell seeding by centrifugal casting and increase hydrogel retention, without compromising the biomechanical properties of the scaffold. Micropores with diameters of 50, 100, and 200 mum were machined at different linear densities in decellularized small intestine submucosa (SIS) planar sheets and tubular SIS scaffolds using an argon laser.

Absorption of bioactive molecules into OASIS wound matrix.

Objective: To examine the ability of OASIS Wound Matrix to absorb, retain, and protect bioactive molecules from solution.

Design: Samples of OASIS Wound Matrix were incubated in solutions of bioactive molecules, specifically heparin, albumin, fibronectin, basic fibroblast growth factor 2, and platelet-derived growth factor (PDGF). Half of the samples were then rinsed, and all of the samples were evaluated using enzyme-linked immunosorbent assays (ELISAs) and dye-mediated spectrophotometric methods for absorption and retention of the bioactive molecules.

Effects of sterilization on an extracellular matrix scaffold: part II. Bioactivity and matrix interaction.

Small intestinal submucosa (SIS) has been successfully used to treat a variety of damaged or diseased tissues in human patients. As a biologic scaffold, SIS stimulates repair of damaged or diseased tissues and organs with tissue that is similar in structure and function to the material it was meant to replace. To meet clinical safety requirements, biologic materials from animal tissues must undergo processing treatments to minimize host immune response and to eliminate the possibility of disease transmission.

Advances toward tissue engineering for the treatment of stress urinary incontinence.

Suburethral pubovaginal sling placement is a common surgical procedure for the treatment of stress urinary incontinence. A wide variety of graft materials is available, each associated with inherent desirable and undesirable characteristics and complications. In this article, we discuss the rationale for and application of small intestinal submucosa (SIS) in lower urinary tract tissue engineering, with emphasis on the use of SIS as a suitable and biologically compatible sling material.

Tissue engineering a clinically useful extracellular matrix biomaterial.

Implantable biomaterials are one of the most useful tools in the surgeon's armamentarium, yet there is much room for improvement. Chronic pain, tissue erosion, and late infections are just a few of the serious complications that can occur with conventional, inert materials. In contrast, tissue-inductive materials exist today.

Interactive biomaterials: taking surgery to the next level.

Medicine has been advanced greatly by implantable biomaterials, but today's standard materials are not without problems. Infection, erosion, adhesions, persistent pain, and other complications suggest that something better is possible. Just as normal tissues self-renew, it is desirable to have an implant recapitulate original anatomy for both structure and function.

Small intestinal submucosa does not promote PAIII tumor growth in Lobund-Wistar rats.

Background: Site-specific remodeling and angiogenesis are two observations associated with the use of small intestinal submucosa (SIS) as a tissue repair graft. Its angiogenic capacity has raised questions concerning its effect on tumor growth and metastasis in clinical tumor resection cases. The effect of SIS on the ability of neoplastic (prostate adenocarcinoma) cells to establish, grow, and metastasize was examined in Lobund-Wistar (L-W) rats.

Virus safety of a porcine-derived medical device: evaluation of a viral inactivation method.

The goal of this study was to evaluate the efficacy of a virus-inactivating process for use during the preparation of porcine-derived extracellular matrix biomaterials for human clinical implantation. Porcine small intestine, the source material for the tissue-engineered, small intestinal submucosa (SIS) biomaterial, was evaluated. Relevant enveloped, non-enveloped, and model viruses representative of different virus families were included in the investigation: porcine parvovirus (PPV), porcine reovirus, murine leukemia retrovirus (LRV), and porcine pseudorabies (herpes) virus (PRV).